1. Field of the Invention
The present invention relates generally to ring networks in which network nodes are interconnected by a ring transmission medium, and more specifically to an information collection technique for the ring network.
2. Description of the Related Art
In the conventional SONET/SDH (synchronous optical network/synchronous digital hierarchy) ring network, each network node holds its own management information. If the network node desires to monitor another network node, it attempts to establishes an inter-node communication path to a maintenance terminal via some intermediate node to access the management information of the desired node. As a result, a substantial amount of time is taken to obtain the necessary maintenance, or alarm message when a trouble occurs in the ring network.